More generally, practice with people who are competent in the attack that you want to defend against. Actual experience beats speculation every time.

Yes, and the bland assertion made by many aikidoka that kicks are easy to defend against needs to be qualified. IMO, the kicks that you're likely to actually encounter in a self-defense situation are easy to defend against, simply because not many people are competent kickers. To generalize that to saying, "Oh, it's easy to defend against a kick," and then go to someone who is actually proficient in one of the kicking styles and invite him/her to try and kick you, is a short trip to being sorry and sore.